Robot Framework 7.0 changes

Update robot code syntax overall in the repo

Changes:
   - Update the requirement.txt package version for robot
   - The '[Return]' setting is deprecated.
      Use the 'RETURN' statement instead.
   - Singular section headers like '*** Test Case ***'
     are deprecated. Use plural format like
     '*** Test Cases ***' instead.
   - Singular section headers like '*** Variable ***'
     are deprecated

Tested:
   - Ran from sandbox with the version
     $ robot --version
     Robot Framework 7.0 (Python 3.10.12 on linux)

     and also tested on latest python version

     Robot Framework 7.0 (Python 3.11.9 on linux)

Change-Id: I54e85f9d799556c63b9a39f79483f83e9b980768
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/extended/code_update/host_code_update.robot b/extended/code_update/host_code_update.robot
index 502a821..728a80f 100644
--- a/extended/code_update/host_code_update.robot
+++ b/extended/code_update/host_code_update.robot
@@ -287,7 +287,7 @@
 
     ${version}= BMC Execute Command
     ...  grep extended_version= ${manifest_path}
-    [return] ${version.split(",")}
+    RETURN   ${version.split(",")}
 
 
 Code Update Test Teardown